Nano-chip hope for oral cancer detection

Gently brushing a lesion on the tongue or cheek can help detect oral cancer, with success rates comparable to more invasive techniques

According to preliminary studies by researchers at Rice University, the University of Texas Health Science Centres at Houston and San Antonio and the University of Texas M.D. Anderson Cancer Centre in the US, gently touching a lesion on the tongue or cheek with a special brush similar to a toothbrush can help detect oral cancer, with success rates comparable to more invasive techniques.

The study, which appeared online in Cancer Prevention Research, compared results of traditional diagnostic tests with those obtained with the novel nano-bio-chip technology developed at Rice University's BioScience Research Collaborative. A sample of 52 participants, all of whom had visible oral lesions, leukoplakia or erythroplakia and had been referred to specialists for surgical biopsies or removal of the lesions, were tested, and a total of 11 diagnosed as healthy, indicating that the nano-bio-chip is 97 per cent "sensitive". It was also shown to be 93 per cent specific in detecting which patients had malignant or premalignant lesions.

"One of the key discoveries in this paper is to show that the miniaturised, noninvasive approach produces about the same result as the pathologists do," said John McDevitt, Brown-Wiess Professor of Chemistry and Bioengineering at Rice, whose lab developed the nano-bio-chip.

Currently patients with suspicious lesions are generally discovered by dentists or oral surgeons, and end up getting scalpel or punch biopsies as often as every six months.

"People trained in this area don't have any trouble finding lesions," said McDevitt. "The issue is the next step - taking a chunk of someone's cheek. The heart of this paper is developing a more humane and less painful way to do that diagnosis, and our technique has shown remarkable success in early trials."

With Rice's new nano-bio-chip technique, results would be delivered in 15 minutes instead of taking several days, as lab-based diagnostics do now. It would also eliminate the need for invasive, painful biopsy.

Researchers claim the chips would also be able to detect when an abnormality turns precancerous. "You want to catch it early on, as it's transforming from pre-cancer to the earliest stages of cancer, and get it in stage one. Then the five-year survival rate is very high," said McDevitt. "Currently, most of the time, it's captured in stage three, when the survivability is very low."

The nano-bio-chip is on the verge of entering a more extensive trial that will involve 500 patients in Houston, San Antonio and England. That could lead to an application for US Food and Drug Administration (FDA) approval in two to four years.

Oral cancer afflicts more than 300,000 people a year. The five-year survival rate is 60 per cent, but if cancer is detected early, that rate rises to as much as 90 per cent.